Hands-On Lab & Phase Exit Prove TaskFlow authorization using multiple users and workspaces
Phase 19 - Authorization, Ownership, RBAC & Permissions Volume 05 - Authentication & Security
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Phase 19 transforms verified identity into contextual, server-side authorization decisions.
Hands-on lab: prove authorization, not UI hiding Complete the lab with at least two Supabase users and at least two workspaces. Authorization is not proven until a caller fails correctly across a resource boundary.
Lab A - Link identity to domain user • Add authSubject as nullable + unique.
• Run migration and generate Prisma Client.
• Sign in as each development user and obtain verified subject from /auth/me.
• Link each subject to the intended TaskFlow User using a trusted development/admin path.
Lab B - Create policy data • Workspace A: User 1 OWNER, User 2 MEMBER.
• Workspace B: User 2 OWNER, User 1 has no membership.
• Assign one Workspace A task to User 2 and keep another task assigned to User 1.
Lab C - Verify matrix Scenario Expected
Level 4 - Engineer Design authorization for an HRIS leave request: employee can view own leave; supervisor can approve direct reports only; HR can view department-wide; payroll can read approved leave dates but cannot approve; system must hide other employees private records. Identify which checks are RBAC, relationship-based, and business-state based.
Phase exit checklist • You can distinguish 401, 403, and scoped 404.
• You can map verified auth subject to a domain user safely.
• You can explain role vs permission vs ownership/relationship.
• You can enforce workspace membership on every request.
• You can prevent ID tampering from crossing workspace boundaries.
• You understand why coarse guards and service-level resource policy both exist.
• You can explain deny-by-default and least privilege.
• You can test vertical and horizontal privilege escalation.
Authorization decides what an authenticated identity may do to a specific resource. UI hiding is never a substitute for server-side enforcement.
Restate the goal of “Hands On Lab and Phase Exit” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: trusted identity → requested action → resource scope → policy decision → allow/deny. Mark the one boundary this lesson changes.
Inspect the current repository state and record the exact files, route, table, or runtime involved. Avoid creating an abstraction before you can name the existing owner.
Implement the smallest vertical slice. Add one coherent change, run the narrowest verification command, and read the output before continuing.
Connect the slice to TaskFlow’s phase artifact: Permission model + guards/policies protecting TaskFlow workspace/task actions with deliberate 401/403/404 semantics.. Verify behavior from the outside as a user or API client would.
Create one controlled failure that is safe to reproduce. Predict the symptom first, capture evidence, locate the earliest broken boundary, then fix only that cause.
Close the reference and rebuild or explain the core change from memory. Record what you would monitor or test before trusting the same change in production.
const canEdit =
user.role === "ADMIN" ||
(user.role === "MEMBER" && task.ownerId === user.id);
if (!canEdit) throw new ForbiddenException();Do not copy this as a finished answer. Predict what each boundary does, type the smallest useful slice, run it, then compare the result with your prediction.
Trace verified identity, role, resource owner/workspace, and policy inputs separately.
Add server-side resource authorization; UI visibility is only experience, never enforcement.
Without copying the final source, create a second small scenario that applies “Hands On Lab and Phase Exit” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Write a matrix test covering at least owner, member, outsider, unauthenticated caller, and missing resource.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.IDOR: trusting a resource ID without proving caller access
Predict the symptom before causing the failure. Then locate the earliest boundary where reality diverges from expectation.Why does this responsibility live here, what input does it trust, what output proves success, and what would go wrong if another layer owned it?
If your explanation is vague, repeat the boundary trace before moving on.Close the reference. Reproduce the core idea from memory or explain the exact request/data flow aloud. Then check your diff or notes for accidental shortcuts that bypass validation, authorization, error handling, or verification earned in earlier phases.